The goal of this application for the renewal of a Research Scientist Award is to discover how chronic conduct problems develop in childhood and adolescence and how serious conduct disorder can be prevented. The PI proposes three programs of research and a plan for professional development. The aim of the first program (funded by NICHD) is to understand basic cognitive and emotional processes in aggressive behavior. It is hypothesized that acquired knowledge structures stored in memory guide an individual's processing of social information, leading to individual differences in behavior. Processing occurs in sequential steps of encoding, interpretation, response generation, response evaluation, and enactment. These processes will be related to aggressive behavior patterns over time in a sample of 259 adolescent boys and girls (40 percent African-American). The aim of the second program (funded by NICHD) is to build a transactional ecosymbiotic model of the development of chronic conduct problems in adolescence. Biological disposition, sociocultural context, and life experience risk factors are hypothesized to lead to conduct problems in additive, interactive, mediational, and reciprocally influential ways. All factors are hypothesized to be mediated by proximal cognitive and emotional processes. The model will be tested in an ongoing longitudinal sample of 585 boys and girls (20 percent African-American) who have been followed since preschool and will reach age 19 during this 5-year period. The aim of the third program (called FAST Track and funded by NIMH) is to create, implement, and evaluate a comprehensive intervention designed to prevent the development of serious conduct disorder in high-risk children. After screening 11,000 kindergarten boys and girls in four geographic sites and three cohorts, 960 children (75 percent boys; 50 percent African-American) were selected as high-risk and randomly assigned to receive intervention or serve as controls. Children will enter high school by the end of the next 5-year period. Analyses will focus on intervention efficacy, predictors of intervention success, process-to-outcome relations, and cost-benefit ratios. The PI's research mentoring includes directing an NIMH-supported training program in developmental psychopathology and prevention research. The PI's professional development plans include advanced training in statistics, psychophysiology, cultural awareness and impact, and prevention policy analysis.